I'm currently rebuilding my network infrastructure and am planning to make my NAS available trough an OpenVPN server running on my router for "outside" use (no port forwarding: NAS in private LAN, available trough the VPN).
Now I was wondering about a certain scenario: let's say, I have mapped some of the NAS's drives as network drives via SMB/CIFS in Windows on my laptop (using the local IP address of the NAS in the LAN) or have a proprietary software of the NAS's manufacturer trying to connect to a certain service on a dedicated port.
If I were to take this notebook to an unsecured, public wifi- would this expose the local LAN IP's and/or ports in the CIFS request or the connection request coming from the proprietary software until I'm connected to my VPN (i.e. in the very moment, I'm connecting to the wifi until the VPN tunnel is up)? Does this depend on the way such a request is implemented in the software?